Hello all, nice place you have here.
I am sorry this question has probably been asked and answered many times here but I looked and couldn't seem to find a question that was close enough to mine so I decided just to ask.
I am using a nickel-chomium resistance heater and I want to control it like a thermostat. I can handle all that, my question is about power source(s). I want to use a single 12VDC power supply to run both the heater and the Arduino. The heater has 4 ohms so that is about 3 amps. I will use a power MOSFET to turn the heater on and off with the gate controlled by my Arduino running at 5VD.
Would it be a bad idea to simply put a 5VDC voltage regulator on the incoming 12VDC rail and power the Arduino off of that? Most of the current should be headed to the heater but I am worried that a passive voltage regulator might be under spec and I may as well just spend the money on a DC to DC converter.
Thank you and sorry again if this has been answered already.